Shock absorber



June18,1929. J. R. SNYD'ER 1,717,526

` SHOCK ABSORBER Original Filed April 26, 1926 III, I

Cil

Patented June 18, k1929.

UNITED STATES PATENT OFFICIEL? meer r.. sNYnnR, or CLEVELAND HEIGHTS,onto."

Application` led April 26, 1926, Serial No. 104,587. Renewed November 8,1928.

This invention relates to shock absorbers and has particular referenceto shock absorbers for motor vehicles in which ,the shock absorber',while permitting the free and unrestricted compression of the mainsprings7 frictionally retards or checks the rebound or expansion stroke.

The main object of the invention is to provide a shock absorber whichAdoes its work effectively and reliably but which is neverthelessinexpensive to manufacture and is durable in construction. In otherwords, it is one of the objects to provide an ellicient, inexpensiveshock absorber which will stand up under the severe use towhich it issubjected without requiring frequent repairs or attention. K. n n

A further object is to provide an improved shock absorber of what may betermed the one-way friction type, that is to say onewhich frictionallyretards or checks the rebound stroke only, saidshock absorber alsohaving what may be termed an idle period permitting, withoutretardation, minor vibrations or movements of the main springs. f

The invention maybe briefly summarized as consisting incertain noveldetails of construction and combinations and arrangements of parts whichwill be described in the specification and set forth in the appendedclaims.

In the accompanying sheet of drawings Fig. 1 is a transversesectionalview through the shock absorber substantially along the line1-1 of Fig. 2.

Fig. 2 is a sectionalview substantially along the line 2-2 of Fig. 1looking in the direction indicated by the arrows. e

Fig. 3 is a fragmentary sectional yview. substantially along the line3-3 of Fig. .2, and

Fie. 4 is a side View of the shock absorber on anslightly reduced scale.

Referring now to the drawings the shock absorber illustrated is designedto be mount ed on the chassis of an automobile and comprises astationary center belt 10 adapted to be secured by suitable fitting tothe chassis frame and rotatable in opposite directions on the centerbolt isa drum 11 to `which is attached in a suitable manner a strap 12adapted to be connected to `the axle of the vehicle and to be woundontoand unwoundfrom the drum as it rotates in opposite directions. Thedrum 11 is preferably formed of two stampings7` one of which forms theperiph- V ery, one side and the hub of the drum and the other which isdesignated 13 forming the opposite side and being reniolvablyy attached,p

to the main stamping.y Between the drum 11 and the centerfboltis anon-metallic bearing 14 preferablyformed of wood andpreferably forcedinto aA laterally extending hubyeoy like flange 15 of the main stampingofthe y drum.

Inside the rotatable drum 11 is a stationary drum 16 which isconcentricwith respect to the rotatable drum and is held stationary bybeing` clamped and preferably also inter-A locked with the end of thecenter bolt 10 by' a bolt 17 which is screwed into a threaded portion ofthe centerbolt, the latter preferably being/hollow ,as illustrated. Thestationary drum 16 as herein illustrated extends outwardly from thecenter bolt then laterallyr toward the side of the mainstamping of drum1.1 and close to the same so as to form with said `stamping a springhousing and then the stationary drum yagain extends outwardly close tothe periphery of drum 11 and then laterally toward thestamping ofy drum11 forming the peripheral portion. This stationary drum constitutesoneof the two frictional members of the device.

yIn the housing just referred'to'is located 'i a spring18 which isadapted to rotate the drum 11 in one direction "so Aastowind the r strapther'eon'during the compression stroke of themain 'springs of thevehicle. In this instance the outer endof spring 18 is held stationaryby being attached to thestationaryr drum 16. This connection can beformed in different ways but in thisv instance a lip 18a yformed on theouter end of spring 18'is exf tended through an openingin the stationary,l

strap thereon during the compressionstroke of themain springs andpermits the drum 11 Thus the spring effective to turn the kdrum 11 inOnedirection so `as to wind the to be rotated in theopposite directionagainst the tension of'spring 18 when the strap is pulled out oruniwound from the drumrdur- *l ingthe yrebound stroke. e d e ',As"lubricant is adaptedto be supplied [to spring 18 to render,y itlsilentin 'action they outer portion ofthe housing for spring 18 ispreferably sealed by a packing strip 19 which in this instance isarranged between the adj acent parallel portions of the two drums andwhich maybe attached to either the rotating or stationary part.` Thislubricant may be supplied to the spring compartment'either through thecenter bolt or directlyY through the side wall of the main stamping ofthe i rotatableV drum. e

The 'other lfriction member which cooperlatesiwith the peripheralportion of stationary drum 16 iszadapted to be rotated by the 1 drum 11.

This second friction member is in this instance arranged inside theperipheral portion of the statonary drum 16 and it consists of aflexible metalV band 2O between which and the inner periphery ofthe drum16 suitable friction material is provided. This friction material whichis shown at 21 may be attached either to the outer surface of bandV `2Oorto theQinner surface of drum 16 but preferably on the'band. Y Y Y slIt will'be noted particularly by reference to Fig. 2 that the frictionmember 2O is substantially circular but preferably the ends are spaced ashort distance apart as illustrated in 2 so that r there willl be a lostmotion connection between this frictionmember and the driving member ofthe drum 11'.y This Vdriving member is in the form'of a finger 22,whichY is attached'tothe stamping 13 and projects laterally inwardVbetween the ends Yof ,the

Ymovable friction member as 'illustrated V'in Figs. 2 and 3. Thisdriving Vmember 22is preferably formed'from a stamping doubled uponitself to form the portion which extends laterally between the ends ofthe friction member20 'and having flange like portions on opposite sidesof the projecting portion se- Y cured by rivets or equivalent fasteningmeans 23 to the stamping 13.

It willbe seen that with this construction l*the ldrum may move back andforth slightly without shifting the movable friction member. yThisallows minor vibrations of the main springs to take place without anyretarding action yby the shock absorber but as the drum 11 'is rotatedfurther in either direction the finger 22 engages one end of the movablefriction member7 preferably the end of the friction material 21 so thatthe engagement will be noiseless, and then. moves the friction memberwith the drum 11. i

In order that the friction member 20 (with fits frictionmaterial 21) maybe expanded so as yto frictionally engage the peripheral wall of thestationary drum 16 and thereby frictionally retardthe rebound stroke ofthe main springs,l and'to automatically contract yso as to be relativelyfree of the'stationary ydrumV during the compressiony of the `main espring provision' is made for at allti'mes yieldinglypressingone end ofthe friction member outagainstthe stationary drum 16, the end whichisthus pressed outward being on the tubular portion of the shoe and theVhead of a pin 27 which is supported on a.

suitable shoulder 28 formed by the inturned lip of the 'stamping 13 ofdrum 11.V The inner end ofthe pin 27 preferably engages a fixed portionof the shoulder andthe shoe 24; preferably engages a ixedportion of thefriction member 2O but inasmuch as there isV a lostv motion connectionbetween the moyable drum 11 and the friction member 2O it 1s desirablethat the shoe 241 have a rocking engagement with the friction band andthe inner end of the pin have a rocking engagement with the shoulder 28of stamping 13. This vresult is accomplished in this instance byproviding the outer part ofshoe 20 with a slot which engages anyinturned lip 29 on the friction band 2O and byforming the head of pin27 in the shape ofy a cone. withthe'point or inner end thereof engagingan opening 'formed in the shoulder or extension 28 against which the pin27 bears'.

The amount'of pressure exerted by the spring 25 on the shoe 24 can bevaried byl adjusting the abutment 26 which ypreferably has a threadedconnection with the tubular portion of the shoe and in orderthat accessmay be had for the purpose of adjustment the portion of the stamping 13opposite the abutment may be provided with a removable or Ymovable door30. Thus it will be seen that when the drum 11 is rotated in a directionsuch that lthe linger 22 engagesthe end of VfrictionV member 20'which ispressed outward,

the friction member 20'may be rotated around the inside of stationarydrum 16 with practically no friction, the band then being contracted.vThis occurs when the drumcll is rotated in a direction lto wind thestrap 12 Vthereon orduring the compression stroke of the main springs. fHowever, during the rebound stroke of the main springs in which eventdrum 11 isrotated in the opposite direc- Ytion the driving finOer 22rotates the fric- 7 i CD tion member 20by its engagement with theopposite end of the'friction member. 1t will be seen at once that whendriving pressure is y(exerted bythe finger in this direction or on ythisendof friction member 20 the latter will be expanded into frictionalengagement with the stationary drum and, therefore, frictionally retardthe rotation of the drum. VThe degree of friction exerted by therotatable fric-v tion member against the stationary drum or "Lait/'bacfriction member duringthe rebound stroke will depend on thedegree ofpressure with which the shoe 24 presses the end ofthe band outwardlygbut this, as already stated, canbe adjusted as desired.

'I hns this shock absorber has the desired action during rotation inboth directions, at the same time providing the free or idle period topermit minor vibrations in the mainsprings without material resistanceby the shock absorber. Additionally this shock absorber is simple inconstruction and therefore durable as well as satisfactory in action.

IVhile I have shown 'the preferable construction I do not desire to beconfined to the precise details shown but aim in my claims to cover allmodifications which do not involve a departure from the spirit and scopeof my invention as defined in the appended claims.

I-Iaving thus described my invention, I claim:

l. A shock absorber comprising a rotatable drum adapted to receive astrap which may be wound thereon and unwound therefrom, a stationarydrum constituting a friction inem ber, a movable friction memberarranged within the stationary drum and means Whereby it is moved inopposite directions relative to the stationarydrun'i by the rotatabledrum as it rotates in opposite directions.

2. In a shock absorber, a rotatable drum having' a strap attachedthereto, a stationary drum constituting a friction member, an ex!pansible and contractable friction band engaging the stationary drum,and means forming a driving connection between the rotatable drum andopposite ends of the band.

8. In a shock absorber, a rotatable drum to which a strap is attached, astationary drum arranged concentric with respect to the rotatable drumand constituting a friction member, a flexible band, means for pressingone end of the band out against the stationary drum, and means forforming a driving connection between the rotatable drum and the bandwhereby the rotatable drum rotates the band in opposite directions.

4C. In a shock absorber, a rotatable drum to which a strap is attached,a stationary drum constituting a friction member, a flexible band, meansfor pressing one end of the band out against the stationary drum, andmeans rotatable with the drum and engageable with opposite ends of theband for shifting it in opposite directions.

5. In a shock absorber, a rotatable drum to which a strap is attached, astationary drum constituting a friction member,aflexibleband, means forpressing one end of the band out against the stationary drum, and a lostmotion drivingconnectionbetween the rotatable drum and the band, bywhich the rotatable drum rotatesthe band in opposite directions.

6. In a shock absorber, a rotatable drum to which ya strap is attached,a stationary drumy constituting a `friction member, a flexible band,means fory pressing one end oftheband against the stationary drum, adriving member rotatable with they drum and extending between the endsof the band, yand serving to rotate the band in opposite directions. y

7. In a shock absorber, a rotatable drum to` whichr a strap is attached,a'stationary drum constituting a` friction member, a flex-y ible band,means for pressingone'end of the band against the stationary drum, adriving member rotatable with the 'drum andeXtending between the endsvof the'band, the ylatter being spaced apart so that a lost motionconnection is provided between the driving member and the band, by whichthe drum rotate the band in opposite directions. n,

8. In a shock absorber, a rotatable drum having a strap attachedthereto, a spring connected to the drum and serving to rotate the samein one direction; a stationary drum arranged inside the rotatable drumand having a peripheral portion adjacent the latter, a flexible frictionband engaging the inner periphery of the stationary drum, means forminga driving connection between the rotatable drum and the band so that theband will be turned in opposite directions by the rotatlable drum andwill frictionally engage lthe 9. In a shock absorber, a hollowrotatablev drum having a strap attached thereto, a sta.-

tionary drum arranged inside the rotatable drum, portions of thestationary and rotatable `r drums forming a housing, a spring in saidhousing and serving to rotate the first named drum in one direction,other portions of the stationary and rotatable drums forming ak frictionchamber, a friction band in the last named chamber engaging the innerside of the peripheral portion of the stationary drum,

and means whereby said friction band isrotated by the drum in oppositedirections relatively freely in one direction and in frictional iengagement with the stationary drum in the opposite direction.

l0. In a shock absorber, a hollow rotatable drum having a strap attachedthereto, a stationary drum arranged inside the rotatable drum, portionsof the stationary and rotatable drums forming a housing, aspring in saidhousing and serving to rotate the irstk named drum in one direction,other portions of the stationary and rotatable drums forming a frictionLchamber, a friction band in the last named chamber engaging the innerside ofy the peripheral portion of the stationary drum,

and means whereby said friction band is ro.r

tated by the drum in opposite directions relatively freely in onedirection and in frictional engagement with the stationary drum yin theY drums forming a'housing, a spring .in said housing and serving torotate the first named drum in one directionfother portions of thestationarygand rotatable drums forming a friction chamber, a frictionband in the last named chamber engaging the inner side of the`peripheral portion of the stationary drum, y

and means whereby said friction band is rotated by the drum in oppositedirections rela` tively freely in onedirection and in rictionalengagement with the stationary drum in the opposite direction, therebeing a lost motion s driving Connection between the rotatable drum andsaid band, and means arranged between la portion of the rotatable drumand ay portonof the Vband Vfor pressing the latter out against thestationary drum.

AIn testiinony'whereof, I hereunto aiiix my signature.V g

` JACOB R. SNYDER.

